fatigue vs grogginess

fatigue and grogginess both are nouns.

Word	Noun	Adjective	Verb	Adverb
fatigue	Yes	No	Yes	No
grogginess	Yes	No	No	No

As nouns, grogginess is a hyponym of fatigue; that is, grogginess is a word with a more specific, narrower meaning than fatigue:

fatigue: temporary loss of strength and energy resulting from hard physical or mental work
grogginess: a groggy state resulting from weariness

Other hyponyms of fatigue include asthenopia, eyestrain, jet lag, exhaustion, logginess, loginess, senioritis.

fatigue (noun)	grogginess (noun)
labor of a nonmilitary kind done by soldiers (cleaning or digging or draining or so on)	marginal consciousness
(always used with a modifier) boredom resulting from overexposure to something	a groggy state resulting from weariness
temporary loss of strength and energy resulting from hard physical or mental work	a dazed and staggering state caused by alcohol
used of materials (especially metals) in a weakened state caused by long stress

fatigue (verb)	grogginess (verb)
exhaust or get tired through overuse or great strain or stress
lose interest or become bored with something or somebody